Cities provide jobs and interesting careers, a flourishing cultural life, a multitude of consumption choices, and rich opportunities for social interaction.

Cities offer their citizens a sense of living in a global world.

But what does urbanization mean for our planet? What is the impact on the climate?

Urban areas are complex and dynamic systems. No town or city is immune from either external forces or internal pressures.

Towns and cities change over time, and this process is both inevitable and hopefully beneficial.

By 2050, it is estimated that 70 % of all people will live in cities. This means that the cities and the infrastructure need to accommodate them and sustain this growth, requiring a delicate balance of social, environmental and economic considerations.

It is worth noting that of the 25 fastest-growing major cities in the world, seven are in China and six are in India. The challenges they face are huge but so are ours.

How can cities grow, provide housing for their new inhabitants, and still preserve green areas and quality of life?

How can infrastructure and transportation develop to meet the needs of a constantly growing population?

I don't have the answers to the questions. But I do believe that we can no longer be narrow-sighted. We have to look over the horizon.

Let us share our successful experiences in order to build a sustainable society.

We have to realize that when changing the composition of nature we change the conditions for human life, flora and fauna.

So let us do it wisely since such change is irreversible. I think about the American Indians who traditionally consider what impact their actions will have on the next seven generations.

We have the responsibility and the power to do right thing the right way. Let us see to it that we take our responsibility. Let us be visionaries!

I am confident that the sharing of knowledge and experience today will be enriching to everyone.

To open this conference and to inspire us all, I would like to quote the Greek philosopher, Aristoteles.